This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Methods: The released N-linked glycan aliquots intended for neutral and amino sugars were hydrolyzed with 400 [unreadable]L of 2.0 N trifluoroacetic acid (TFA) at 100[unreadable]C for 4 h. The hydrolysates were lyophilized, resuspended in H2O, sonicated for 7 min in ice and transferred to injection vials. A mix of standards for neutral and amino sugars with a known number of moles was hydrolyzed in the same manner and at the same time as the samples. Four concentration of standard mix (0.5, 1.0, 2.0, and 4.0 nmoles per injection) were prepared to establish a calibration equation. The number of moles of each residue in the sample was quantified by linear interpolation from the calibration equation. The neutral and amino sugars were analyzed by HPAEC using a Dionex DX500 system equipped with a GP40 gradient pump, an ED40 electrochemical detector, and a Thermo-Separation AS3500 autosampler containing a stainless steel needle. The individual neutral and amino sugars were separated by a Dionex CarboPac PA20 (3 x 150 mm) analytical column with an amino trap. The gradient programs used eluents A - degassed nanopure water, and B - 200 mM NaOH. Injections were made every 40 minutes. All methods were based on protocols described by Hardy and Townsend (Hardy, M. R., and Townsend, R. R., "High-pH anion-exchange chromatography of glycoprotein-derived carbohydrates", 1994, Methods Enzymol. 230: 208-225). Instrument control and data acquisition were accomplished using Dionex PeakNet software, version 5.01.